Download Maximizing Safety in Contact Lens Wearers

AOA Contact Lens and Cornea Section, 2010,
Student-Resident Essay Award Submission:
The Role of the Eye Care Professional in
Maximizing Safety for Contact Lens Wearers
Supported by: CIBA Vision
Submitted by: Jaelyn McComas, OD
Primary Care Resident,
Indiana University School of Optometry
The Role of the Eye Care Professional in
Maximizing Safety for Contact Lens Wearers
AOA Contact Lens and Cornea Section, 2010
Jaelyn McComas, OD
Table of Contents
Page
Introduction
3
FDA’s Role
3
Contact Lens Modalities
4
Adverse Events
7
Contact Lens Care and Handling
8
Ophthalmic Drops
12
Daily Considerations
13
Education and (Non)Compliance
15
Future
17
References
18
2
Introduction
There are many factors that contribute to the safety of contact lens wear, beginning
with the research and development team who create the products through to the marketing
team who promote the products to potential wearers. Relevant issues include optimizing
oxygen transport to ensure that no oxygen deficit occurs to the cornea, ensuring product
biocompatibility with the ocular surface and any associated care system, and providing
consumers with recommendations on how to appropriately wear and care for their lenses.
The eye care practitioner’s role is to ensure the patient is a good candidate for lenses,
determine the most appropriate lens through careful fit and evaluation, and prescribe the
lens and solution combination to meet the needs of the patient. It is the eye care
practitioner’s responsibility to continually encourage the safe use of contact lenses through
meaningful instruction regarding contact lens wear time, replacement schedule, and by
reinforcing compliance to lens hygiene and lens storage case care. Every patient encounter
provides the opportunity to promote the adherence to recommendations, thereby
establishing improved contact lens hygiene habits and maximizing the safety of contact lens
wearers. A recent Contact Lens Leadership Summit concluded that, “contact lenses are a
safe, effective, very useful, and, for many, an essential way of giving sight to some 120
million people around the world.”2 For this reason, it is vital to maximize the safe use and
care of this medical device.
FDA’s Role
The US Food and Drug Administration (FDA) regulates contact lenses, for vision
correction as prescription devices and as decorative purposes, and lens care products
through the Federal Food, Drug, and Cosmetic Act. Pre-market and post-market public
safely are the primary concerns of the agency. The MedWatch program processes adverse
3
event reports from the consumer and industry24. The Federal Trade Commission (FTC)
regulates advertising and marketing of devices to protect consumers from injury11.
Contact Lens Modalities
There are many contact lens modalities to choose from. It is the eye care
practitioner’s responsibility to select an appropriate lens/solution combination to meet the
patient’s needs based on a comprehensive history. With each contact lens modality there is
a required wear time and replacement schedule prescribed by the eye care practitioner that
must be followed to ensure safe, comfortable vision. This maintenance schedule is part of
safe contact lens care and compliance.
Soft Contact Lenses (SCL)
There have been many advances made in soft contact lens materials that provide
healthier, safer options for contact lens wearers. Many believe the lenses made of high
oxygen-permeable silicone hydrogel material are the lenses of choice for most eyes,2 due to
the decreased signs of corneal hypoxia, regardless of whether the lenses are worn on a daily
wear basis or overnight. This lens material is selected when patients use their lenses in an
extended wear modality, and are typically replaced every month. However, it is ultimately
the eye care practitioner who decides the replacement schedule on a case-by-case basis.
Conventional SCL Wear
Contact lenses are worn during the day only and removed for sleep. This requires
an appropriate cleaning and lens storage regimen, which is prescribed by the eye care
practitioner.
4
Disposable Contact Lenses
Daily disposable (inserted, removed, and discarded daily) and extended wear
disposable (inserted, slept in for a period, removed, and discarded) lenses are a convenient,
safe option because the patient can avoid cleaning and storage of the lenses when the
patient follows the safety rule of never re-inserting a used lens3. These lenses are used for a
limited time before discarded; therefore, they have decreased safety concerns. People with
sensitivities to solutions or buildup on lenses can safely return to daily disposable contact
lens wear. It is important to note that overnight wear of contact lenses increases the risk of
contact lens related complications. Another safety risk is taken when a patient chooses to
over wear disposable lenses for any reason (i.e. economical interest), thereby putting the
health of the eyes at risk.
Extended Wear (EW), Continuous Wear (CW) and Flexible Wear
EW is approved for overnight use up to 6 consecutive nights (7 days). It is important
to remove the lens one night a week. The FDA has approved continuous wear (CW) contact
lenses for up to 30 nights (31 days) of consecutive wear without removal. Flexible wear is
considered sleeping in approved EW or CW lenses occasionally, but lenses are worn
predominately on a daily wear basis. Each time lenses are removed they must be properly
cleaned and disinfected before reinsertion. EW lenses were first approved for the treatment
of aphakia and later for non-aphakic ametropia24.
Gas Permeable (GP) and Specialty Lenses
An often over-looked option over the past 10 years, particularly for new lens fits,
relates to the use of gas permeable lenses. It is estimated that only 10% of lens fits now
occur with this modality. It is a healthy, extremely safe choice because of the lens material’s
5
high oxygen permeability and transmissibility, and low rate of deposition of tear film
components. Several studies have demonstrated that GP lenses result in reduced corneal
binding of bacteria to corneal epithelial cells than soft contact lenses21. GP lens materials
have the lowest prevalence of microbial keratitis infections (1.48/10,000 eyes annually)
compared to all other types of contact lenses, under both daily and extended wear
conditions21.
The safety of overnight orthokeratology GP lenses for the correction of myopia is
discussed in the literature with expressed concern for more research. The issue that
requires investigation is if the epithelial barrier is compromised when the corneal
reshaping mechanism induces central epithelial thinning27,30. Many patients can benefit
from this treatment. However, the concern involves the safety risk associated with a
compromise in the epithelial barrier and that this device of myopia management is targeted
toward the adolescent population.
A recent study found Menicon Z material GP lens for the treatment of aphakic
infants and children to be safe and effective with no observable increase in the rate of
infection during the six month study period while lenses were being worn on a one-week
EW basis23.
Decorative (Plano) Contact Lenses
Decorative contact lenses, or cosmetic lenses, are not intended to correct vision but
to alter the appearance of the eye. In the past, these contact lenses have been obtained
without a prescription and have been used without the supervision of an eye care
practitioner. This poses a serious public safety concern for the increased risk of contact lens
related adverse events. The FDA issued a health notice in 2002 informing consumers of the
6
risk involved when using unapproved decorative contact lenses and advised consumers to
seek a qualified eye care professional for all contact lens needs13 .
Adverse Events
The most serious adverse event eye care practitioners would prefer to avoid is an
infection causing microbial keratitis (MK), as it is the most serious complication with
potentially severe ocular morbidity. Microbial keratitis can occur while wearing any contact
lens modality19,28 but typically is more prevalent with overnight wear of soft contact lenses
made from low oxygen permeable material10. Additional risk factors reported in association
with MK are lens hygiene practices, smoking, overnight wear and male gender28.
Unfortunately, advances in the development of silicone hydrogel material and daily
disposable contact lenses have not reduced the incidence of this potentially sightthreatening event26. A major investigation, The Australian and New Zealand Microbial
Keratitis Study, recently reaffirmed the infrequency of contact lens related infections:
4/10,000 daily wear and 20/10,000 extended wearers annually20,28. Overnight contact lens
wear increases the risk of MK by approximately four times19.
Other non-sight threatening contact lens related complications include
inflammatory, mechanical, or hypoxic events such as: contact lens–induced peripheral ulcer
(CLPU), infiltrative keratitis (IK), contact lens-induced acute red eye (CLARE), vascularized
limbal keratitis (VLK), asymptomatic infiltrates (AI), asymptomatic infiltrative keratitis
(AIK), and conjunctival papillary reactions.
7
CL Care and Handling
Contact lenses are contaminated through handling, storage, and lens wear. A study
in Australia32 reported that recommendations for contact lens case hygiene are inconsistent
and inadequate among sources responsible for providing this safety information to contact
lens wearers. However, the contact lens industry, the FDA, and optometrists are more
consistent regarding instruction and recommendations for adequate contact lens
disinfection32. This finding is an important reminder for contact lens authorities to reduce
the confusion regarding recommendations for contact lens case hygiene and to highlight the
necessary steps to achieve improved safety, comfort, and success for contact lens wearers.
Hand Washing
Proper hand washing is a prerequisite to safe contact lens handling. The objective is
to decrease the transmission of microorganisms from the hands, to the lens, and into the
eyes. A rule of thumb is to avoid touching eyes, handling contact lenses, and the storage
case, without washing hands thoroughly. The CDC recommends washing hands with soap
and clean running water. Begin by rubbing hands together and scrub all surfaces with
lathered soap for 20 seconds. Rinse hands well under running water and dry hands
completely [preferably with a lint-free towel for contact lens wearers]. Finally, use the towel
to turn the faucet off4. This established hand-washing technique is recommended to be
performed by all health care practitioners and contact lens wearers before handing lenses
to prevent the spread of infection.
8
Disinfecting Soft Contact Lenses: Multi-Purpose Solution and Hydrogen Peroxide
Solution
There are two types of solutions on the market: Multi-Purpose Disinfecting Solution
(MPS) and a hydrogen peroxide solution. Most contact lens wearers favor the MPS solution
because it is convenient and does not require a neutralization period before insertion of
lenses.
Contact lens wearers who use hydrogen peroxide disinfection modality suffer less
solution-related adverse events than those who use MPS solution. Hydrogen peroxide is the
solution of choice for patients with chemical sensitivities because the solution is selfpreserving (no added preservative) and the resultant products after the neutralization
period are water and oxygen. For this reason, hydrogen peroxide disinfecting solution is the
safest and most effective disinfection system2,17. If contact lenses have been stored for a
week or more without being worn, it is advisable to repeat the disinfecting process
completely before wearing lenses again15,28.
The ‘rub and rinse” technique of lens care continues to be an important part of
decreasing contact lens contamination. In 2008, the Center for Devices and Radiological
Health (CDRH), Ophthalmic Devices Panel Advisory Committee, issued a letter in response
to the recent outbreaks of Fuscarium and Acanthamoeba infections to the contact lens care
product corporations reinstating, “that there is improvement in lens care when using a
"rub-and-rinse" regimen as compared to a "rinse alone" regimen. This is because "rub-andrinse" regimens help prevent microbial adhesion to the contact lens, help prevent formation
of biofilms, and generally reduce the microbial load on the lens and the lens case.”12,32 It is
highly recommended to rub and rinse lenses before and after lens disinfection and storage15
with the disinfection solution. The rub and rinse step should be done with a sterile saline
solution before and after disinfecting lenses with hydrogen peroxide.
9
Never ‘top up’ old solution in the contact lens storage case with new solution;
always use fresh solution with each disinfection procedure. Be mindful to rinse and rub, and
disinfect lenses thoroughly every time the contact lens is removed. Any bacterial
contamination introduced through handling, storage, or wearing the contact lenses will be
greatly reduced by carefully following these recommended guidelines for contact lens care
and hygiene.
Disinfecting Gas Permeable Lenses
Gas permeable lens care requires more steps than SCL care. Every time the GP lens
is removed it should be cleaned with daily cleaner to remove deposits, stored in disinfecting
solution, then rubbed and rinsed with saline or disinfecting solution before insertion. Do
not use tap water for rinsing, nor storing GP lenses. It is strongly advised not to use tap
water in conjunction with children’s lens care2. The objective is to avoid contamination of
the lens by microorganisms commonly found in potable water. The eye care practitioner
may suggest an enzyme treatment to be used once a week to remove allergy-inducing
protein deposits. Before inserting the lens a wetting solution may be used to aid in comfort3.
Contact Lens Storage Case Care
Contact lens case hygiene is an often over-looked component of safe contact lens
wear. Cases can be a major source of contact lens contamination, which could lead to
serious infection. A recent literature review16 found the main pathogenic microorganisms
that contaminate contact lens cases include: Pseudomonas, Serratia, Staphylococcus,
Acanthamoeba and Fusarium. Hall and Jones recommend patients to clean and disinfect lens
cases daily, avoid using tap water, replace cases regularly, and to consider where (i.e. as far
away from the toilet as possible) and how cases/lids are stored while lenses are being worn.
10
Bathrooms are a known source of microorganisms; therefore, patients should be counseled
to store their lenses, cases, and care products in a clean, dry environment16.
Recent, updated recommendations for case care is to rub and rinse the case with the
MPS solution, dry with a clean lint-free cloth, and store the case and lids upside down on a
clean tissue while not in use16,28. Frequent replacement of the lens storage case is important
to minimize contamination32. Replacement suggestions for a contact lens case range from
monthly to every 6 months, or replacement with each new bottle of solution.
The latest innovation is an antimicrobial lens storage case, which is impregnated
with silver (CIBA Vision, Duluth, GA) for use with Aquify Multi-Purpose Solution (CIBA
Vision); this technology can decrease lens case contamination, especially microbial biofilms
formed on the case walls31. This system performs best when then lid is recapped when it is
not in use, i.e. avoid air-drying32.
Solution and Contact Lens Material Compatibility
Not all lens types and solution combinations are compatible17. The corporations
who receive FDA approval assume responsibility for producing a product that is compatible
with all lenses on the market or to make available to the public the product’s restrictions2.
Likewise, the eye care practitioner must be aware of these interactions to prescribe an
appropriate MPS solution with prescribed silicone hydrogel lenses. Hydrogen peroxide is
very safe and causes the least corneal staining with silicone hydrogel lenses compared to
any MPS solution28.
Dr. Andrasko has produced an online reference tool called, “Andrasko’s Corneal
Staining Grid” to aid the eye care professional in selecting a biocompatible contact lens
material/brand and multipurpose solution. The results from his grid are based on small
studies that demonstrate the average corneal staining area at two hours. This staining grid
11
is accessible online at www.staininggrid.com. The purpose of this biocompatibility study is
to determine which lens/solution combinations do not cause excessive corneal staining. A
second goal of this study is to establish if corneal staining affects lens comfort1. Another grid
available online is called the Itoi Grid (www.staininggrid-japan.com).
Ophthalmic Drops
Artificial Tears, Rewetting Drops
Contact lens wear may exacerbate asymptomatic dry eye; a lubricating drop may be
indicated to prevent corneal desiccation with soft contact lenses. There are numerous
rewetting drops on the market approved for use with contact lenses, in alphabetical order:
Aquify Comfort Drop (CIBA Vision, Duluth, GA), Boston Rewetting Drops (Bausch &Lomb,
Rochester, NY), Blink Contacts (AMO Abbott, Santa Ana, CA), Clerz Plus (Alcon, Fort Worth,
TX), Complete Blink-N-Clean (AMO Abbott, Santa Ana, CA), Complete Lubricating and
Rewetting Drop (AMO Abbott, Santa Ana, CA), Opti-Free Express Rewetting Drop (Alcon,
Fort Worth, TX), and ReNu Rewetting Drop (Bausch & Lomb, Rochester, NY). Drops
indicated for use with soft contact lenses can be safely used with GP lenses, but GP lens
rewetting drops are not recommended to be used with soft contact lenses. There are many
lubricating drops that are not compatible with contact lenses. It is imperative for the safety,
clarity of vision, and longevity of the lens, that an appropriate rewetting drop is prescribed
with contact lens wears. Eye care practitioners may consider offering a sample when
dispensing lenses to encourage the use of a drop that is compatible with contact lenses.
Ocular Therapeutic Drops
In some instances it is desirable to increase contact time of a medication on the
ocular surface, thereby benefitting from the uptake and release properties of a SCL.
12
However, most therapeutic ocular drops are not to be used concomitantly with soft contact
lenses because SCL are permeable and may absorb the medication or preservative in the
drop. The uptake property of the SCL effectively increases the concentration of the eye drop
in the contact lens, which may provoke an ocular toxicity reaction. The alternative is that
the lens may draw in the medication and delay the onset of the action of the drug, thereby
decreasing its effectiveness. An additional risk is that some hydrogel contact lenses deform
in the presence of therapeutic drops and can become a safety concern to the cornea18. A
recent study measured the uptake of two ophthalmic drops with hydrogel soft contact
lenses; the study found that zwitter ionic SCL are, “highly safe for wear with concomitant
use of eye drops based on its high contour stability and low uptake of substances applied to
the eye.”18
Daily Considerations
Tap Water
Tap water hosts a variety of bacteria, some of which can be dangerous for the eye.
Patients should be instructed to close their eyes tightly in the shower (or remove lenses)
and while washing their face28. Leak-proof goggles should be worn in swimming pools,
lakes, and hot tubs.
Make-up
Cosmetics can be a source of ocular infection or irritation, and cause dirty, deposited
contact lenses. Some suggestions to avoid cosmetic-related complications with contact lens
wear include: apply makeup after the insertion of contact lenses, do not borrow or lend
cosmetics to others, wash or replace application brushes frequently, do not apply eyeliner
to lid margins, and do not apply cosmetics to a red, swollen, infected eye.
13
Seasonal Allergies and Contact Lens Use
Daily wear disposable contact lenses are ideal for allergy sufferers, as allergens that
build up on the lens during the day are tossed away and a fresh lens is inserted the next
morning.
Spectacles
It is imperative that contact lens wearers also have a pair of current prescription
spectacles to use in the event of misplaced contact lenses, and illness. Contact lenses should
be removed if lenses are associated with symptoms of pain, discomfort, redness, or
decreased vision.
Monovision
It is important to warn monovision patients to be aware of decreased stereopsis
with this presbyopic correction option. FDA recommends prescribing driving spectacles to
meet the state Department of Motor Vehicles requirements24.
Ultra-Violet Absorbing Contact Lenses
UV absorbing contact lenses can be useful to help prevent the formation of cataracts,
ARMD, and contribute to the general health of the eye. While not a replacement for
sunglasses, UV blocking contact lenses that cover the limbus provide protection at least
equivalent to wrap-around sunglasses or goggles7.
14
Occupational Safely
National Institute for Occupational Safety and Health (NIOSH) recommends,
“Workers be permitted to wear contact lenses when handling hazardous chemicals
provided that the safety guidelines are followed and that contact lenses are not banned by
regulation or contraindicated by medical or industrial hygiene recommendations. However,
contact lenses are not to be used as an eye protective device, and wearing them does not
reduce the requirement for eye and face protection”6. Therefore, it is imperative that CL
wearers are educated regarding the necessity of safety eyewear while wearing contact
lenses. Numerous studies have found additional safety benefits to contact lens wearers
while using appropriate safety wear protection: contact lenses can provide some safety to
the cornea in an eye splashed with chemicals, from ice/snow in cold environments, some
forms of blunt trauma, and can offer protection from foreign body, or mechanical hazards7.
Education and (Non) Compliance
Eye care practitioners require regular continuing education regarding current
guidelines for lens care, contact lens use, and maintenance to provide excellent patientcentered care. In the event of a contact lens complication, timely diagnosis and appropriate
treatment will increase the likelihood of a positive outcome19.
Preventative medicine is taking measures to educate and instruct patients regarding
CL safety. Patient compliance can be a reflection of the eye care practitioner’s clear, direct
contact lens hygiene recommendations. Education should be simple, easy to remember, and
direct. Patients prefer to have a reason why they must perform steps in lens care hygiene. It
is helpful to have a contact lens care routine that has enough redundancy to safeguard the
patient even when they are not compliant8. Spend time building relationship with patients
to gain their trust and make suitable, informed choices by prescribing appropriate lenses
15
for how they will be used. Patient lens care hygiene can be monitored effectively by using
open-ended questions and asking the patient for a demonstration of their lens care routine.
Each contact lens appointment should have some time allocated to review and monitor
contact lens care and compliance. This is a good time to update the patient’s lenses to a
newer technology material that provides a greater safety margin.
Noncompliance is a multifaceted problem that involves patient knowledge, attitudes
and beliefs, and available resources8. Variables that contribute to noncompliant behavior in
contact lens wearers include: age, education, duration of time wearing contact lenses,
wearing schedule, and the purpose for wearing contact lenses8. Patients can develop a sense
of self-assurance once comfortable in a routine and begin to ‘cut corners’ in lens care and
case hygiene. Noncompliance in medical management varies from 24.8 – 44% and the rates
for contact lens care noncompliance ranged from 50 – 99%8. One study indicates that many
contact lens wearers thought they were compliant but reported various noncompliant
behaviors8.
Remind patients to use extreme caution if purchasing contact lenses from someone
other than an eye care professionals, for example over the internet. Contact lenses are
regulated medical devices and are not to be purchased without a valid prescription. Do
stress to the patient the importance of regular routine contact lens appointments whether
the patient is symptomatic or not.
Always and Never
Encourage the contact lens wearing patient to always ask: “Do my eyes look good?
Feel good? Can I see well?” If the patient answers ‘no’ to one of these questions they should
remove their contact lens and talk to their eye care practitioner immediately22. Patients should be
instructed to never go to bed with a painful red eye but to seek help immediately.
16
Future
The Institute for Eye Research is investigating antibacterial contact lenses by
embedding fimbrolides and selenium onto the surface of the contact lens31. “By developing
an antibacterial contact lens that prevents bacterial adhesion we are hoping to reduce the
occurrence and severity of infection and inflammation caused by various microbes.”9
Further investigation needs to be done in developing new antibacterial surface technologies
for contact lenses, and lens cases that circumvent patient contact lens hygiene noncompliance; these innovations are not a substitute for providing regular contact lens
recommendations and exceptional education.
In the meantime, lens hygiene education by eye care practitioners, and marketing by
industry, is of utmost importance for the continued safe use of contact lenses worldwide.
Regular comprehensive eye exams and predetermined contact lens follow-up appointments
lend themselves to regular opportunities to remind patients of the limitations and
restrictions of safe lens use, and to review appropriate lens care habits. Based on studies, it
is prudent to emphasize the increased risk of infections associated with poor case hygiene.
During these discussions, the clinician can recommend safer contact lens modalities,
particularly when patient compliance is questionable. Although, contact lens care presents a
public health concern, it is important to keep in mind that contact lens wear is a safe, viable
corrective lens option for most people. The wealth of contact lens knowledge continues to
expand. Through the dedication of all those in the specialty field of contact lenses concern
is evident in providing and updating safe contact lens options, and by elaborating on safe
lens care practices. This is an exciting time for eye care practitioners to move forward with
a gold standard in contact lens hygiene guidelines and with the united purpose of
maximizing the safety of contact lens wearers.
17
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